1. Field of the Invention
The present invention relates to mats, webs or facers coated with an inorganic coating. More specifically, the present invention relates to mats, webs or facers for the building construction industry, such as gypsum board, fiberglass facers and thermosetting polyisofoam insulation board facers coated with a silicate.
2. Description of the Related Art
Conventionally, organic binders such as a polymer latex are used in high solid coatings for fiberglass mats or other surfaces. It is well known to use latex coatings for a fiberglass mat facer in gypsum board application or other application such as polyisofoam insulation board facers. Inorganic binders such as sodium silicate (liquid glass) are believed to be too brittle in those applications. Silicates such as sodium silicate are also generally believed to be not usable in coatings exposed to hot and/or humid conditions for long period of time. See, for example, U.S. Pat. Nos. 6,770,354 and 5,112,678.
Liquid sodium silicates are solutions of water soluble glasses made from varied proportions of sand (SiO2) and soda ash (Na2CO3). They range in viscosity from slightly sticky fluids to thick substances that resist flow. The more siliceous silicates (2.8 to 3.2 ratio) have long been used as dependable, low cost adhesives. Sodium silicate adhesives are used for bonding a variety of porous surfaces and materials such as paper, perlite, mica and wood.
Enhancing the flame resistance, fire resistance and mold resistance of materials in the building construction industry is always an important objective. Providing novel materials having such enhanced properties is an objective of the present invention.